Sheet metal worm



Nov. 9, 1937. w J STUBER 2,098,439

'SHEET METAL WORM Filed June 13, 1936 Patented Nov. 9, 1937 SHEET DIETAL WORM Walter J. Stuber, Philadelphia, Pa., assignor to Carey-McFall 00., Philadelphia, Pa., a corporation of Pennsylvania Application June 13, 1936, Serial No. 85,170 7 Claims. (01. 74-458) This invention relates to the slat-tilting mechanism of a Venetian blind. The present application includes divisible subject matter originally disclosed in my copending application Serial No.

52,725, filed December 3, 1935 and additional matter constituting a continuation thereof.

The invention involves primarily a novel form of worm gear employed in the tilting mechanism and wherein the worm is composed of a plurality of sections each constituting a predetermined segment of a convolution of the worm spiral and which may vary from.a full three hundred and sixty degree segment to any divisible part thereof, depending upon the nature of the worm desired.

The object of the invention is to provide a quiet acting worm gearing which will tilt the slats and lock them in any desired position with a minimum of effort and at a maximum speed.

The construction and operation of the invention forming the subject matter of the present application will be fully disclosed herein-after, reference being had to the accompanying drawing, of which:

Fig. 1 is a front elevation of the tilting mechanism;

Fig. 2 is a face view of the tilting mechanism, partly in section as viewed onthe line 2-2, Fig. 1 and showing one form of worm within the scope of the invention;

Fig. 3 is a sectional elevation taken on the line 3-3, Fig. 2;

Figs. 4, 5, and 6 illustrate details of the worm shown in Figs. 2 and 3;

Figs. '7 and 8 show details and assembly of a development of the worm shown in Figs. 1 to 6;

Fig. 9 is a view similar to Fig. 2 showing a still further development of the worm;

Fig. 10 shows a face view in detail of one of the worm segments of Fig. 9;

Fig. 11 is a top edge view of the segment shown in Fig. 10;

Fig. 12 is a side edge View of the segment shown in Figs. 10 and 11; and

Fig. 13 is a section taken on the line I3-I3,

Fig. 10.

The device as origin-ally disclosed in application Serial No. 52,725 includes the features disclosed in Figs. 1 to 6 inclusive.

The blind structure usually comprises a head rail (not shown) which is adapted to support and solely carry the whole of the blind structure, including the tilting mechanism of the present case.

Secured tothe under side, and at the opposite ends respectively, of the head rail is a pair of blind-supporting brackets, one of which is shown at 2, which support the tilting rail 4. The blind proper is attached to the tilting rail 4 and, as usual, comprises a series of substantially parallel, horizontally disposed and vertically spaced slats 5 which are supported by and between laterally spaced pairs of ladder tapes. The ladder tapes consist of the usual side tapes connected by the usual cross tapes which underlie the slats and retain saidslats in said predetermined vertically 10 spaced relation to each other, when the blind is in the fully extended or maximum low position. The upper ends of the ladder tapes are connected to the tilting rail 4. r

In order to provide for pivotal or lateral tilting 15 movement of the tilting rail 4 and the slats carried thereby the tilting rail 4 is provided at one end with a suitable trunnion which has bearing in the bracket located at that end of the tilting rail which has been omitted from the present draw- 20 mg.

The opposite end of the tilting rail 4 is mounted on, carried by, and permanently secured to an element forming a detachable part of the tilting mechanism. In the present instance, such ele- 25 ment comprises a plate or wheel 5 in which is secured a laterally extending trunnion stud B, said stud being pivotally and removably mounted in a bearing opening formed in the bracket 2 and arranged in axial alignment with the trunnion at the opposite end of the tilting rail 4.

The-plate 5 has a lateral extension 1, below the pivot 6, which extends under and is secured to the under surface of the tilting rail 4, by screws, bolts, or other suitable means 8. 35

For the purpose of tilting the rail 4 and the slats carried thereby to desired angles relative to the plane of the Window, the plate 5 is provided With gear or worm teeth 9 throughout a segment of a circle swung from the axis of the 40 stud 6, as clearly shown in Fig. 2.

Meshing with the teeth 9 of the gear segment is a double pitch worm l0. Said worm is composed of two identical parts Illa-40a, pressed from fiat sheet metal and each comprising a hub section 45 l I and a segmental rim section l2 formed integral therewith, said rim, section, in that form of the Worm shown in Figs. 2 to 6 inclusive comprising a segment of a circle to the extent of substantially I other, and the two segmental rim sections l2, I2

in overlapping relation at the ends I3 and I4 thereof and forming a full circle with the overlapping ends spaced apart laterally, i. e. axially of the worm, to provide an opening I5 of sufiicient width to accommodate one of the teeth 9 of the tilting plate or wheel 5 therebetween, the peripheral edges and margins of the segments I2, I2 of the worm parts IIlaId working respectively in alternate spaces between the teeth 9 of the tilting plate 5, whereby the efiect of the double pitch worm and. worm gear is provided. 7

Fig. 6 illustrates the two parts I0a-Illa in the course of being assembled to provide the complete worm I0 shown in Figs. 2 and 3.

By rotation of the worm III, the tilting-plate 7 may be rocked about the common axis of the trunnions of the tilting rail 4 to an extent of substantially 180, whereby the slats may be rocked in either direction from their normally parallel horizontal planes, for example, to a substantially Vertical plane and wherein the edges of the slats will lie in closely adjacent or overlapping relation to each other, to close the window opening substantially completely.

The tilting movement is limited by the ends of the worm sections engaging untoothed portions of the tilting plate or wheel 5 when said plate has arrived at either one or the other of its limits of tilting.

The tilting worm is securedto one end of a tilting spindle which is flattened on one or both sides adjacent one end to receive a correspondingly shaped opening 2I in each of the worm sections Illa and by which the two sections film-Illa of the worm are keyed to the spindle 20, said sections being firmly held in fixed relation to each other and to said spindle by riveting the end of the spindle over the outer section,'as indicated at 2I, and pressing the inner section against a shoulder 22 formed on the spindle, as by the above noted flattening of the spindle.

The tilting spindle 20 is rotatably mounted in a suitable bearing 23 formed in the bracket 2 by splitting the bracket and pressing alternate portions between the slits outwardly in one direction "from the plane of the bracket 2 and the intermediate and outermost portions of the plate in the opposite. direction.

The end of the spindle 20, opposite to that on which the worm I0 is secured, is provided with a sheave wheel 25 which, like the worm I0, is composed oi'two disks pressed from sheet metal and of identical construction, these disks being dished and placed together in axial alignment and with their convexed surfacesin abutting relation to each other to provide a groove for the reception of an operating cord or chain 24.

In the present instance, a common form of ball chain is provided to pass around the sheave, and in order to prevent a slippage between the sheave and the operating chain the dished disks of which the sheave is composed are radially corrugated adjacent the periphery thereof to provide suitable pockets for receiving the balls of the operating chain.

In order to hold the balls within the recesses of the operating sheave a guard 26 is provided around the periphery, of the wheel 25, said guard comprising a flange 21 formed on a plate 28 which is freely rotatably mounted on the operating spindle 20 between one end of the'bearing 62 and the inner face of the sheave 25.

The sheave 25,.like the worm I0, is secured to the spindle 20 by riveting a flattened shouldered end of the spindle over the outer disk of the.

pitch worm I0 meshing with the teeth 9 of the tilting plate 5 may be moved to either of its extreme positions and locked therein by the intermeshing of the worm I0 with the worm teeth 9, or at any intermediate position between said extremes.

Fig. 8 shows four discs I0bIIIb of the kind shown in FigJl, as including each a 180 segment of a convolution of the worm spiral and arranged with the end I3b of one in abutting relation to the end. Mb of another of the segments with the side marginal edges I2b-I2b flush, to produce a continuous smooth thread of the worm spiral. These parts*I0bI0b and I0bIIlb are arranged in pairs with the hubs IIbI lb of each pair in axial abutting relation to each other and with a spacer sleeve or collar 30 between the pairs.

Figs. 10, 11, 12, and 13 illustrate a worm wherein each part IIlc thereof includes a complete 360 segment of a circle constituting one complete convolution of the worm spiral, each section or part Ific being composed of a circular disc, see Fig. 10, having a central opening 2Ic in the central hub portion IIc thereof and from which to the outer marginal edge I20 the disc is split radially on the line aa, providing two ends I30 and I40. These ends are spread apart axially of the worm, as seen in Figs. 11 and 12 and in that way form the spiral convolution of the worm.

The two sections IOc-Illc are fitted together as illustrated in Fig. 13 and in order to do so the hub section IIc of each part We is off-set at opposite sides of the split line a-a, as illustrated at 3I-in Fig. 13, to opposite sides respectively of a median plane :r-a:, the offsets 3I, 3I being connected by an angular web portion 32 which forms shoulders 33. and 34 on each hub section IIc against which edges 35 and 36 paralleling'the split line a-a of the other section abut, the two portions Illa-I00 thereby becoming interlocked one with the other to complete the worm which in its assembled form is adouble pitch, double spiral worm by which quiet operation is obtained because of the fact that there is at all times more than one tooth of the worm wheel 5 in intermeshing engagement with the worm and this eliminates any noise'that may be produced by the half segments of the worm shown in Figs. 2 and -3 coming into engagement with the teeth of the worm wheel alternately.

Obviously, the wormshown in Figs. '7 and 8 or that shown in Figs. 9 to 13 may be substituted for the worm shown'in Figs. 2 to 6 without departing from the spirit of the invention.

I claim:

1. In a Venetian blind tilting mechanism including a tilting wheel having circumferentially spaced teeth, a worm cooperating with said toothed wheel and comprising a plurality of identical parts respectively including a central hub section and a peripheral marginal section constituting a segment of a convolution of the worm spiral with said hub. and marginal sections being integral and of substantially uniform thickness over the entire areas thereof in the direction of the axis of the worm and with the marginal section of each part disposed in a plane arranged at an. angle to the plane of the hub section of said part, said parts being assembled in intermeshing relation to each other with the hub sections thereof in substantially parallel and axial aligned relation one with the other and predetermined portions of said spiral segments of an intermeshing pair of said identical parts spaced apart axially of said worm to receive single teeth of said tilting wheel thereb-etween.

2. In a Venetian blind tilting mechanism including a tilting wheel having circumferentially spaced teeth, a worm cooperating with said toothed wheel and comprising a plurality of identical parts respectively including a central hub section and a peripheral marginal section constituting at least a 180 segment of a convolution of the worm spiral with said hub and marginal sections being integral and of substantially uniform thickness over the entire areas thereof in the direction of the axis of the worm and with the marginal section of each part disposed in a plane arranged at an angle to the plane of the hub section of said part, said parts being assembled in intermeshing relation to each other with the hub sections thereof in substantially parallel and axial aligned relation one with the other and predetermined portions of said spiral segments of an intermeshing pair of said identical parts spaced apart axially of said worm to receive single teeth of said tilting wheel therebetween.

3. In a Venetian blind tilting mechanism including a tilting wheel having circumferentially spaced teeth, a worm cooperating with said toothed wheel and comprising a plurality of identical parts respectively including a central hub section and a peripheral marginal section constituting a segment greater than 180 of a convolution of the worm spiral with said hub and marginal sections being integral and of substantially uniform thickness over the entire areas thereof in the direction of the axis of the worm and with the marginal section of each part disposed in a plane arranged at an angle to the plane of the hub section of said part, said parts being assembled in intermeshing relation to each other with the hub sections thereof in substantially parallel and axial aligned relation one with the other and predetermined portions of said spiral segments of an intermeshing pair of said identical parts spaced apart axially of said worm to receive single teeth of said tilting wheel therebetween.

4. In a Venetian blind tilting mechanism including a tilting wheel having circumferentially spaced teeth, a worm cooperating with said toothed wheel and comprising a plurality of identical parts respectively including a central hub section and a peripheral marginal section constituting substantially a complete convolution of the worm spiral with said hub and marginal sections being integral and of substantially uniform thickness over the entire areas thereof in the direction of the axis of the worm and with the marginal section of each part disposed in a plane arranged at an angle to the plane of the hub section of said part, said parts being assembled in intermeshing relation to each other with the hub sections in substantially parallel and axially aligned relation one to the other and with the marginal sections of an intermeshing pair of said identical parts spaced apart axially of the worm to receive a tooth of said tilting wheel therebetween.

5. In a Venetian blind tilting mechanism including a tilting wheel having circumferentially spaced teeth, a worm cooperating with said toothed wheel and comprising a plurality of identical parts respectively including a central hub section and aperipheralmarginalsection constituting substantially a complete convolution of the worm spiral with said hub and marginal sections being integral and of substantially uniform thickness over the entire areas thereof in the direction of the axis of the worm and with the marginal section of each part disposed in a plane arranged at an angle to the plane of the hub section of said part, said parts being assembled in intermeshing relation to each other with the hub sections in substantially parallel and axially aligned relation one to the other and with the marginal sections of an intermeshing pair of said identical parts spaced apart axially of the worm to receive a tooth of said tilting wheel therebetween, said hub sections each being offset to opposite sides respectively of a median plane perpendicular to the axis of said worm at opposite sides respectively of a plane axially bisecting said worm providing for interlocking of said parts in the assembled worm.

6. In a Venetian blind tilting mechanism including a tilting wheel having circumferentially space-d teeth, a worm cooperating with said toothed wheel and comprising a plurality of identical parts respectively including a central hub section and a peripheral marginal section constituting substantially a complete convolution of the Worm spiral with said hub and marginal sections being integral and of substantially uniform thickness over the entire areas thereof in the direction of the axis of the worm and with the marginal section of each part disposed in a plane arranged at an angle to the plane of the hub section of said part, said parts each being divided along a line extending radially from the axis to the peripheral edge thereof, said parts being assembled in intermeshing relation to each other with the hub sections in substantially parallel and axially aligned relation one to the other and with the marginal sections of an intermeshing pair of said identical parts spaced apart axially of the worm to receive a tooth of said tilting wheel therebetween, said hub sections each being offset to opposite sides respectively of a median plane perpendicular to the axis of said worm at opposite sides respectively of a plane axially bisecting said worm providing for interlocking of said parts in the assembled worm and forming radially extending shoulders on each part adapted to be engaged by radial edges respectively of the part interlocking therewith.

'7. In a device of the character described, the combination of a bracket, a toothed tilting wheel pivotally mounted on the bracket, a double screw worm rotatably carried by the bracket and cooperating with the teeth on said tilting wheel, said worm comprising a pair of axially aligned hubs each provided with a segment of one convolution of the screw with the opposite ends of each of said segments in overlapping relation to the opposite ends respectively of the other of said segments and space-d apart laterally a sufiicient distance to receive one of the teeth of the tilting wheel therebetween.

WALTER J. S'I'UBER. 

